1. Field of the Invention
The present invention relates to an image processing apparatus, and more particularly to an apparatus for processing image signals having different numbers of pixels by using memory.
2. Related Background Art
Conventionally, there is known a digital VTR which is integrated into a video camera for recording an image signal which has been captured by means of a video camera onto a magnetic tape as an image signal. Further, in recent years, a digital VTR has been developed which is equipped with a memory card slot, and which records moving image data onto a magnetic tape in a conventional manner, and which is also capable of recording a still image onto the memory card.
Meanwhile, due to the improvement of semiconductor technology in recent years, the number of pixels in CCDs has increased dramatically, and one can conceive of even a digital VTR employing a CCD that has more pixels than that of conventional, to capture and record a still image.
However, the conventional digital VTR is designed based on the premise that the moving image data and still image data are signals having exactly the same number of pixels. Therefore, when the number of pixels in the CCD is increased as mentioned above and the number of pixels in the still image data are also increased as a result thereof, it is then no longer possible to deal with the signals easily.
Further, in recent years, due to the stabilization of circuit properties and decrease in electrical power consumption, it has become normal to arrange a moving image processing circuit, a still image processing circuit and other various circuits including memory on the same integrated circuit.
However, when the number of pixels of the image signal is increased, memory having memory capacity corresponding to the number of pixels of the image data is necessary particularly for still image processing. However, when the memory for the still-image processing is also arranged onto the same integrated circuit, then it is not possible to add only the memory alone, or exchange the memory for another memory having larger capacity. Therefore, it was necessary to redesign the integrated circuit each time the number of pixels of the image signal is increased, and this involves significant labor and costs.